Leaving the party encamped at a small pool of fresh water, Sturt and Hume pushed ahead to look for more, but without success. Before leaving they were startled, one afternoon, by a loud report like a distant cannon, for which they could in noway account, as the sky was clear and without a cloud. [These strange reports have since been frequently heard, often at the same moment, at places more than a hundred miles apart. The cause is generally ascribed to atmospheric disturbances.] The advance was now checked, no fresh water could be found on ahead, and their animals were weak and exhausted. Sturt christened the river the Darling, and gave the order to retreat. As they again approached Mount Harris on the Macquarie, where they expected to find a relief party with fresh supplies, fears began to be entertained regarding the safety of those who might be awaiting them at the depôt. The reed beds were in flames in all parts, and the few natives they met displayed a guilty timidity, and one was observed with a jacket in his possession. Their fears were, however, fortunately vain, the natives had made one attempt to surprise the camp, but it had been frustrated, and the relief party had now been some three weeks awaiting the return of the explorers. Sturt rested for some days, during which time Hume made a short western trip.. to the south of the marsh land. He reported that for thirty miles the country was superior to anything they had yet seen, and exceedingly well watered; beyond that distance the plains and brush of the remote interior again resumed their sway. On the 7th March the party struck camp and made for the Castlereagh, the relief going back to Bathurst. On the 10th they reached the Castlereagh, and found it apparently without a drop of water in its bed. From here downwards the old harassing hunt for water commenced once more, and as they descended the river they were further puzzled by the intricate windings of its course and the number of channels that intersected the depressed country they were travelling through. On the 29th they again struck the Darling, ninety miles above the spot where they had discovered it: "This singular river still preserved its character so strikingly that it was impossible not to have recognised it in a moment. The same steep banks and lofty timber, the same deep reaches, alive with fish, were here visible as when we left it. A hope naturally arose to our minds, that if it was unchanged in other respects, it might have lost the saltness that rendered its waters unfit for use; but in this we were disappointed-even its waters continued the same."